Restore Your Truck’s Core Performance and Reliability
Is your 2016-2018 GMC Sierra 1500 acting up? Dealing with a frustrating no-start condition, erratic engine behavior, or a persistent Check Engine Light can bring your work and life to a halt. As a technician with over two decades of experience, I’ve seen countless drivers struggle with these exact issues, which often trace back to a failing Engine Control Module (ECM). This isn’t just a part; it’s the brain of your engine, and when it falters, everything else does too. We offer a dependable solution: a replacement Engine Control Module, part number 12674472, delivered to your door already programmed with the latest GM software for your specific vehicle.
Forget the hassle and high cost of dealership programming. Simply provide us with your truck’s Vehicle Identification Number (VIN) after your purchase, and our experts will flash the module for you. This ensures that when you receive the part, it’s ready for installation and configured to communicate perfectly with your truck’s systems. This is the most direct path to getting your Sierra running smoothly again.
From the Diagnostic Bay
I remember a 2017 Sierra 1500 that came into the shop with a really tricky intermittent stalling problem. The owner had already replaced the fuel pump and a few sensors with no luck. The truck would run fine for days, then die at a stoplight without warning. No consistent codes were being stored, just a generic U0100 (Lost Communication with ECM) every once in a while. After checking all the wiring and grounds, we hooked up a scope to the ECM’s power and data lines. We found that the module’s internal voltage regulator was dropping out randomly, causing the processor to reset. A new, correctly programmed 2016-2018 Sierra 1500 ECM fixed it. The crucial last step was the Vehicle Theft Deterrent relearn. Without it, the new ECM wouldn’t allow the engine to start. It’s a simple procedure with the right scan tool, but it’s absolutely essential for the repair to be successful.
Common Signs Your Sierra’s Engine Computer is Failing
A faulty ECM can manifest in numerous ways. If you’re experiencing any of the following, your engine computer is a likely suspect. Look out for these tell-tale signs:
- ✔ Vehicle will not start or has trouble starting.
- ✔ Persistent Check Engine Light (CEL) with codes like P0601, P0606, or communication errors.
- ✔ Poor fuel economy and engine performance, including misfires or rough idling.
- ✔ Intermittent stalling or hesitation during acceleration.
- ✔ Transmission shifting issues or failure to shift.
- ✔ Apparent failure of other sensors or modules that rely on the ECM for communication.
Your Step-by-Step Installation Roadmap
Installing your new ECM is a manageable task for a confident DIYer or any professional mechanic. Following these steps will ensure a smooth process. Remember, your new module comes pre-programmed to your VIN, which handles the most complex part of the job.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the ECM: On most 2016-2018 Sierra 1500 models, the ECM is located in the engine compartment on the driver’s side (LH front).
- Disconnect Connectors: Carefully release the locking tabs and unplug the wiring harnesses from the old module. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket and remove it from the vehicle.
- Install the New ECM: Mount your new, pre-programmed ECM in place and securely fasten it.
- Reconnect Everything: Plug the wiring harnesses back into the new module, ensuring they click securely into place. Reconnect the negative battery terminal.
- Perform Relearn Procedures: This is a critical final step. If the truck does not start, you must perform the Vehicle Theft Deterrent System (VTDS) relearn using a compatible GM diagnostic tool (like Tis2web/Techline Connect). Other procedures, such as a crankshaft variation relearn, may also be necessary depending on your vehicle’s specific needs. This is the responsibility of the installer.
Verified to Fit These GM Models
This module is a direct-fit replacement for several GM vehicles and part numbers. Please verify your part number or match your vehicle from the list below. This ECM is a compatible replacement for part numbers: 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815.
- ✔ 2016-2018 Sierra 1500 Pickup
- ✔ 2016-2018 Silverado 1500 Pickup
- ✔ 2017-2018 Sierra Denali 1500
- ✔ 2017 Escalade / Escalade ESV
- ✔ 2017 Tahoe / Yukon / Yukon XL 1500 / Suburban 1500
- ✔ 2017 ATS (3.6L, VIN Y)
- ✔ 2017 CTS (6.2L Supercharged or 3.6L Twin Turbo)
- ✔ 2017 Corvette
- ✔ 2017 XTS (3.6L, VIN 8)
Frequently Asked Questions
Do I need to send my old ECM back (core charge)?
No core charge is required for this part. You can keep or responsibly dispose of your old module.
What exactly is a ‘theft relearn’ procedure?
It’s a security handshake between your new ECM and the vehicle’s Body Control Module (BCM) and ignition key. If this procedure isn’t done, the anti-theft system will prevent the engine from starting. This requires a professional scan tool with GM software access (Tis2web/Techline Connect).
Is this a plug-and-play part?
It is ‘plug-and-program-play.’ We handle the programming to your VIN before shipping. You handle the physical installation and the final, on-vehicle security relearn procedure. This saves you a trip to the dealer for initial programming.
What if I install this and my truck still won’t start?
First, confirm the Vehicle Theft Deterrent relearn was performed correctly, as this is the most common reason for a no-start after installation. If the issue persists, double-check all connections and ensure there isn’t an underlying issue (like a bad wire or another failed component) that was misdiagnosed as a faulty ECM.
How do I provide my VIN number?
After you complete your purchase, you will receive instructions on how to send us your 17-digit VIN. We cannot program and ship your module without it.
Will this fix my specific check engine light codes?
This module is the correct fix for internal ECM failure codes like P0601 (Internal Control Module Memory Check Sum Error). However, if you have codes for specific sensors (e.g., O2 sensor, MAP sensor), you should diagnose those components first, as the ECM is often reporting a problem, not the cause of it.